Well, what can we say, except that this had a good idea and then they tried to be too clever and added twists and turns and red herrings and a whole salad of things that didn't make sense in how this was supposed to play out.
Acting was meh....the script was meh...the direction was...meh...you're seeing a pattern here.
So, when the final reel kicks in, suddenly we find out it isn't who they kept pointing to, but someone entirely new, that we were given all but zero clues about previous to the "reveal". Ugh. If you're going to spring a new suspect upon us, who is actually the guy, you have to give us something about him beforehand. We saw him enough...but then got no real clues given at all, nothing. This is just lazy.
I'm reminded of the film "Murder By Death", in which the host of the 'party' complains about this kind of stuff, that new information is suddenly introduced with no prior allusion or inference to it throughout the story; it's just dropped in our lap. It's infuriating.
And that describes how we feel about this film, infuriated that it went from promising to utterly disappointing so quickly by trying to be too clever for its own good.
The people who made this film have no understanding of how this kind of story has to play out. They have numerous examples to reference...and yet they blew it by doing the unforgiveable.
Just move on and don't bother.